[h323plus] Failed to set video capability in my video conferencebased on openh323

[Simon Horne]

H.261 is now a plugin codec in H323plus. However looking at the error, it
appears you have not properly defined your capability as it fails in
HMH323_H261Capability::Compare and it looks like a casting issue

Make sure you have these lines at the top of HMH323_H261Capability::Compare

if (!PIsDescendant(&obj, HMH323_H261Capability))
    return LessThan;

Simon

====================
Simon Horne
email. s.horne at isvo.net
Principal Maintainer
h323plus Library

Consulting and Contracting
consulting at h323plus.org.
========================


> -----Original Message-----
> From: h323plus-bounces at lists.packetizer.com
> [mailto:h323plus-bounces at lists.packetizer.com]On Behalf Of Áøäé
> Sent: Tuesday, January 15, 2008 5:04 PM
> To: h323plus at lists.packetizer.com
> Subject: [h323plus] Failed to set video capability in my video
> conferencebased on openh323
>
>
> Hi everybody,
>    I am developing a video conference based on openh323, right now,  I
> failed to set video capability in my system.
>   I wrote a new class named HMH323_H261Capability, derived from
> H323_H261Capability.
>
> class HMH323_H261Capability : public H323_H261Capability
> {
> 	PCLASSINFO(HMH323_H261Capability, H323_H261Capability)
> public:
> 	HMH323_H261Capability(unsigned qcifMPI, unsigned cifMPI, BOOL
> temporalSpatialTradeOff=TRUE,
> 		BOOL stillImageTransmission=FALSE, unsigned maxBitRate=850);
> 	virtual PObject *Clone()const;
> 	virtual H323Codec *CreateCodec(H323Codec::Direction
> direction) const;
> };
> When the program begin, I use
> SetCapability (0, 1, new HMH323_H261Capability (0, 1, TRUE, FALSE,
> 8192)); and the program runs OK, However, when I connect MCU by
> calling
> H323EndPoint::MakeCall(remoteParty, NULL, token, userData); the
> program throw exception and exit.
> Here is the call stack
> KERNEL32! 7c812a5b()
> MSVCRTD! _CxxThrowException at 8 + 57 bytes
> MSVCRTD! __RTDynamicCast + 383 bytes
> H323Capability::Compare(const PObject & {...}) line 427 + 23 bytes
> PObject::operator==(const PObject & {...}) line 1452 + 22 bytes
> H323Capabilities::FindCapability(const H323Capability & {...}) line
> 2075 + 26 bytes
> H323Capabilities::Merge(const H323Capabilities & {...}) line 2375
> + 21 bytes
> H323Connection::OnReceivedCapabilitySet(const H323Capabilities &
> {...}, const H245_MultiplexCapability * 0x013f2c44,
> H245_TerminalCapabilitySetReject & {...}) line 4315 + 18 bytes
> H245NegTerminalCapabilitySet::HandleIncoming(const
> H245_TerminalCapabilitySet & {...}) line 603 + 48 bytes
> H323Connection::OnH245Request(const H323ControlPDU & {...}) line
> 3784 + 18 bytes
> H323Connection::HandleControlPDU(const H323ControlPDU & {...}) line
> 3742 + 18 bytes
> H323Connection::HandleControlData(PPER_Stream & {...}) line 3726
> + 18 bytes
> H323Connection::HandleControlChannel() line 3666 + 18 bytes
> H245TransportThread::Main() line 599
> PTLIBD! PThread::MainFunction(void *) line 1168
> _threadstartex(void * 0x013e8ce0) line 212 + 13 bytes
> KERNEL32! 7c80b683()
>
> In the H323Capability::Compare
> PObject::Comparison H323Capability::Compare(const PObject & obj) const
> {
>   PAssert(PIsDescendant(&obj, H323Capability), PInvalidCast);-->Failed
>
> Can anyone tell me the problem?